Recommendations: 1) Take concrete steps to improve the recording of statelessness, namely by harmonising quantitative data on stateless persons and ensuring that the statistical categories cover the entire stateless population in Belgium, including stateless people in immigration detention and removal procedures. 2) Improve the identification of stateless persons and persons at risk of statelessness in removal procedures and detention centres, including through staff training, and ensure access to the judicial procedure to determine statelessness. 3) Take concrete steps to protect stateless people from arbitrary detention, including introducing a mechanism to identify (risks of) statelessness during the decision to detain, and implementing a thorough assessment of vulnerability and appropriateness of alternative measures in each individual case. 4) Ensure that the treatment of stateless persons, including those in immigration detention, fully complies with its international obligations, and that alternatives to detention are implemented to protect against arbitrary detention in all circumstances. ISSUE 2 – Deprivation of nationality on national security grounds 16. Under international law, States have traditionally been granted broad discretion in the regulation of nationality matters. However, this is not an absolute discretion. States' prerogative in nationality matters has been gradually limited by the evolution of human rights law. The Principles on Deprivation of Nationality as a National Security Measure,28 and the UNHCR Guidelines on Statelessness No 5: Loss and Deprivation of Nationality, provide important clarification, 29 respectively from a wider international law perspective and more specifically in relation to the 1961 Convention. Accordingly, State Principles on Deprivation of Nationality as a National Security Measure, March 2020, available at: https://files.institutesi.org/PRINCIPLES.pdf. The Principles were drafted by ISI in collaboration with the Open Society Justice Initiative and with support from the Asser Institute and Ashurst LLP. They were developed over a 30-month research and consultation period, with input from more than 60 leading experts in the fields of human rights, nationality and statelessness, counter-terrorism, refugee protection, child rights, migration and other related areas. At the time of submission, they have been endorsed by over 100 individual experts and organisations, including leading academics, UN Special Rapporteurs and Treaty Body members, litigators, judges, parliamentarians and diplomats. The Principles restate or reflect international law and legal standards under the UN Charter, treaty law, customary international law, general principles of law, judicial decisions and legal scholarship, regional and national law and practice. They articulate the international law obligations of States and apply to all situations in which States take or consider taking steps to deprive a person of nationality as a national security measure. More information is available here: https://www.institutesi.org/year-ofactionresources/principles-on-deprivation-of-nationality. 29 UN High Commissioner for Refugees (UNHCR), Guidelines on Statelessness No. 5: Loss and Deprivation of Nationality under Articles 5-9 of the 1961 Convention on the Reduction of Statelessness, May 2020, HCR/GS/20/05, available at: https://www.refworld.org/docid/5ec5640c4.html. The Guidelines provide authoritative guidance on the interpretation of Articles 5 – 9 of the 1961 Convention on the Reduction of Statelessness. They draw on the Summary Conclusions of the Expert Meeting on Interpreting the 1961 Statelessness Convention and Avoiding Statelessness Resulting from Loss and Deprivation held in Tunis, Tunisia on 31 October - 1 November 2013. 28 6